Study analyzes impact of dam construction in Amazonian regions

WASHINGTON, D.C. 5/7/12 (PennWell) -- A report released by the Center for International Environmental Law suggests that hydroelectric development in the Andean Amazon could have a significant, negative environmental impact.

The study, conducted by a team led by scientist Matt Finer, analyzes a portfolio of 150 planned dams and hydropower projects across all six major river basins connecting the Andes Mountains to the Amazon River. The study spans Bolivia, Brazil, Colombia, Ecuador and Peru.

These 150 projects represent a 300% increase in the number of existing hydropower plants in the region, and more than half of them would have capacities greater than 100 MW. The study says more than 40% of the projects are in "advanced" planning stages.

Finer says the breaks created in river connectivity between protected Andean headwaters and the lowland Amazon concern him most. "These results are quite troubling given the critical link between the Andes Mountains and the Amazonian floodplain," Finer says.

About 60% of the projects would create the first such major break on their respective waterway, according to the study.

"There appears to be no strategic planning regarding possible consequences to the disruption of an ecological connection that has existed for millions of years," Finer says.

Such connectivity is important, says Finer, because the Andes supply the vast majority of sediment, nutrients and organic matter to the Amazon floodplain. Likewise, many Amazonian fish species only spawn in Andean-fed rivers, including many that migrate the length of the rivers.

The report also notes that more than 80% of the proposed dams would cause forest loss, and more than half are classified as "high impact."

"We conclude that there is an urgent need for strategic basin scale evaluation of new dams and a plan to maintain Andes-Amazon connectivity," says co-author Clinton Jenkins, biologist at North Carolina State University.

The Center for International Environmental Law was established in 1989 and has offices in Washington, D.C. and Geneva. The organization offers legal counsel, advocacy and policy research in a number of areas related to environmental law.